Hydraulic stoker control



Fah, g 15332, D MELLER 1,844,517

HYDRAULI C STOKER CONTROL Filed April 27, 1951 Patented Feb. 9, 1932 UNITED STATES PATENT OFFICE HYDRAULIC STOKER CONTROL Application filed April 27, 1931.

This invent-ion relates generally to the con trol of a fire in a furnace and more particularly to a hydraulic stoker control apparatus combined with means for regulating the amount of air supplied to the tire in the furnace.

One of the disadvantages of present day devices of this character lies in the fact that the amount of power required to operate them is substantially the same regardless of the speed of the stoker. That is, the full amount of power is delivered by the prime mover regardless of the speed of operation of the stolter driving means and whenever the stoker driving means is reduced in speed the excess of power is dissipated or wasted in one way or another. For instance, as set forth in my patent application for automatic regulator for stokers, Serial No. 281,32at, filed May 28th, 1928, the energy furnished by the prime mover remains constant and whenever the hydraulic motor for operating the stoker is running atpart load the remaining energy in the fluid furnished by the prime mover is dissipated and changed into heat due to the passage of the fluid through a throttle valve. Obviously such devices or mechanisms are extremely wasteful of power and it is one object of the present invention to eliminate such difiiculty.

Another diiliculty which accompanies the diiliculty just recited lies in the fact that the oil becomes heated and hence is more difficult to handle. This comes about by the viscosity of the oil changing and hence the operating characteristics of the pump also change.

Briefly described my invention consists of an ordinary hydraulic motor connected to the stoker mechanism to drive the same, a hydraulic piston pump driven by a motor, and suitable connections therebetween. A control means, either manual or automatic,

w regulates louvers to control the air furnished the coal during its combustion, the air blower Serial No. 533,142.

as is necessary to expel the chosen amount of fluid from the cylinder pump. In this way the energy or electricity furnished the constant speed motor is kept at a minimum thus giving economical operation.

Another advantage lies in my positioning the louver-s on the intake side of the fan and maintaining the speed of the fan constant at all times. The control of the amount of air is governed by the position of the louvers. The fan delivers full static air pressure even though the total volume may be decreased or increased and thus combustion is facilitated.

The invention will be apparent from the following description taken in connection with the accompanying drawings and the general characteristics will be summarized in the claims.

In the drawings Fig. 1 is a perspective view illustrating my invention applied to a typical boiler installation.

Fig. 2 is an elevation of the boiler installation shown in Fig. 1 this View being somewhat diagrammatio and parts being shown in cross section in order to expedite the showing.

Similar numerals refer to similar parts throughout the several views.

The numeral 10 designates a steam boiler equipped with my novel sliding door structure 1.1 and an underfeed stoker 12. A hopper 13 feeds the coal into the stoker 12 in the usual manner.

A suitable hydraulic motor 14, having an inlet pipe 15 and an outlet pipe 16, drives the ram or stoker 12 in the usual manner.

A reservoir 20 receives a fluid 21, such as oil, and provides a base for the support of the constant speed motor 22 and the pump 23, the motor driving the pump, the pump being of the reciprocating piston type, through the gears 24. The pipe 15, previous ly mentioned, isconnected with the outlet of the pump whereby the oil or fluid is forced through this pipe, the quantity and pressure of the oil determining the rate of operation of the hydraulic motor 14, whereby the amount of fuel which is fed to the furnace is governed.

The return pipe from the hydraulic motor 14 leads back into the reservoir 20 and a release valve 17 is connected between the outlet pipe-15 and the return pipe 16 whereby the pressure fluid may b'y-pass directly from the outlet pipe 15 to the reservoir without passing through the hydraulic motor 14. This operation would occur when the hydraulic motor 14 was rendered inoperative for any reason, as, for instance, the obstruction of the ram 12 by means of a rock or piece of hard metal.

a An intake pipe 25 leads from the reservoir to the pipe 23, this intake pipe having a control o'r throttle valve 26 and a lever 27 extends from this valve wherebythe same may be opened and closed. When it is desired to decrease the speed of the hydraulic motor 14 and consequently, the amount of fuel entered into the furnace, the control valve 26 is partly closed and hence only part of the pumps cylinder is filled with fluid and hence the degree of movement of the hydraulic motor 14 is lessened. If an increase in speed of the hydraulic motor 14 is desired the valve 26 is opened with the result that more pres sure fluid is transmitted to the hydraulic motor 14 and consequently more fuel is fed to the furnace. The control of the valve 26 may be either manual or automatic.

The shaft on the motor 22 extends through blower casin 40 and supports a fan rotor 41 which is driven at a constant speed. The casing 40 continues in a passageway 42 whereby air is led to the combustion chamber of the boiler 10. The casing 40 hasan opening in which louvers 44 are pivotally mounted, arms 45 extending from the ends of the several axes of the louver and a vertical connecting rod 46 pivotally connected to each of these arms and being pivoted in turn to a bell crank '29 pivoted on the casing as clearly shown in the drawings. A link28 connects one arm of the bell crank 29 with the lever 27 of the control valve and thus the vanes or louvers 44 are synchronously operated with the control valve 26.

Theboiler 10 has a pressure control means 50 which actuates a rod 51 in a vertical direction. The movement of this rod 51 controls the movement of the bell crank 29 which in turn controls the amount of air which is fed to the furnace and also the rate of the flow of coal thereto.

For example, should the pressure within the boiler rise the pressure responsive means 50 will cause the rod 51 to travel downwardly thus moving the bell crank so as to partly close the louvers 44 and hence decreasing the amount of air which is fed to the furnace. Simultaneously the control valve 26 will be partly closed and hence the amount of fluid fed to the hydraulic motor 14 will be decreased and the amount of coal fed to the furnace will also be decreased. Thus as less coal is fed into the furnace less air is proportionately fed thereinto.

Having thus revealed my invention, I claim as new and desire to secure the following combinations and elements, or equivalents thereof by Letters Patent of the United States:

1. In combination, a furnace having a stoker, a fluid operated motor for actuating said Stoker, a reciprocating pump for supplying fluid to the fluid motor, draft devel-' oping means for the furnace including a fan, a constant speed power means for actuating both said fan and said reciprocating pump, means for controlling the input of fluid to the cylinder of said pump whereby the amount of fluid which leaves the pump cylinder is controlled, means for controlling the output of said fan and means responsive to the amount of c vailable energy in the furnace acting to simultaneously actuate said pump control means and said fan output control means, said means for controlling the output of said fan comprising closure means on the intake side of the fan whereby the amount of air accessible to the fan is controlled.

2. In combination, a furnace having a stoker, a fluid operated motor for actuating said stoker, a pump for supplying fluid to said motor, means for controlling the amount of fluid supplied to the pump whereby the speed of the fluid operated motor is governed and means for driving said pump at a constant speed.

3. Ina device of the character described, a furnace having a stoker, a fluid operated motor for actuating said stoker, a reciprocating pump for supplying fuel directly to said motor, and valve means on the intake side of the pump whereby the amount of fluid supplied thereto is controlled.

4. A device comprising the elements as set forth in claim 3, but further characterized by the fact that the valve means is automatically operated by pressure responsive means.

5. In a steam boiler having a. furnace therefor the combination of a stoker for said furna'c'e, a fluid operated motor for operating the iao Stoker, a pump for supplying fluid directly to said motor, valve means on the inlet side of said pump for controlling the amount of fluid which enters the same, pressure responsive means connected to the steam boiler and automatically operable according to the pressure Within the boiler and means connecting the pressure responsive means and the valve means whereby the valve means is controlled by the pressure responsive means.

In testimony whereof I affix my signature.

DALE O. MILLER. 

